Crystallization of murine major histocompatibility complex class I H-2K^b with single peptides

X-ray quality crystals of a soluble murine class I H-2K^b molecule complexed with three different peptide antigens were grown in several forms by streak seeding and macroseeding methods. Co-crystals with VSV-8 (RGYVYGQL), OVA-8 (SIINFEKL) and SEV-9 (FAPGNYPAL) peptides were grown either from NaH₂PO₄ K₂HPO₄ or from polyethylene glycol 4000 within the pH range 5·0 to 7·5, with the use of 4-methyl-2-pentane diol (MPD) as an additive. The VSV-8 crystals grew in space groups P1, with cell dimensions a =63·1 A ̊, b = 69·1 A ̊, c = 72·0 A ̊, α = 89·9 °, β = 77·1 °, γ = 123·3 ° and P2₁2₁2, with a = 138.1 A ̊, b = 88·6 A ̊, c = 45·7 A ̊, and diffract to 2·9 and 2·3 Å, respectively. Crystals of the SEV-9 complex grew from similar crystallization conditions to those of the orthorhombic VSV-8 complex with similar cell parameters and diffract to at least 2·5 Å resolution. Crystals of the OVA-8 complex were obtained from either phosphate (space group C2, a = 118·7 A ̊, b = 61·6 A ̊, c = 85·3 A ̊, β = 108·4 °) or polyethylene glycol (space group P1, a = 64·5 A ̊, b = 71·0 A ̊, c = 66·3 A ̊, α = 89·7 °, β = 95·7 °, γ = 123·3 °) and diffract to 3 Å resolution. The crystallization procedures used here significantly increased the rate and production of X-ray quality crystals.